Canine acquired pneumonia caused by Bordetella bronchiseptica

Here, we present the case of a 55-year-old male with HIV and persistent lymphopenia who developed a paroxysmal severe cough for over three weeks. Microbiology studies were positive for abundant colonies of Bordetella bronchiseptica. He reports that his dog was also ill with a severe cough, suggesting a possible canine-to-human transmission. This zoonosis has been increasingly recognized and possesses significant morbidity and mortality, especially in immunocompromised hosts.

Here, we present the case of a 55-year-old male with HIV and persistent lymphopenia who developed a paroxysmal severe cough for over three weeks.Microbiology studies were positive for abundant colonies of Bordetella bronchiseptica.He reports that his dog was also ill with a severe cough, suggesting a possible canine-tohuman transmission.This zoonosis has been increasingly recognized and possesses significant morbidity and mortality, especially in immunocompromised hosts.

Case
A 55-year-old male presented to the pulmonary clinic with a history of episodic productive cough for three weeks.The cough was productive with brown, blood-tinged sputum, paroxysmal episodes severe enough to induce emesis, and mild hemoptysis.He denied fevers, chills, or rigors.He had pleuritic chest pain that worsened during the coughing spells and progressive mild to moderate dyspnea on exertion.His medical history included HIV with persistent lymphopenia despite HAART (lymphocyte CD4 count of 55 cells/cmm, CD4% of 11%), HIV viral load 25 copies/mL, persistent leukopenia, Kaposi's Sarcoma status post chemotherapy and radiation therapy.His medications included emtricitabine 200 mg daily, tenofovir alafenamide 25 mg daily, etravirine 400 mg, raltegravir 1200 mg daily, sulfamethoxazole-trimethoprim 800 mg /160 mg daily.His family history was positive for diabetes mellitus in his mother and heart disease in his brother.On physical exam, he had a temperature of 97.9 F, heart rate of 86 bpm, oxygen saturation of 94% on room air, and blood pressure of 113/79 mm Hg; he was alert and in no distress, the skin was normal, respirations were non-labored, and was not actively wheezing.The heart exam had no murmurs, and he had no lower extremity edema.
The patient reports living at home with his dog, who had been coughing multiple times before his illness.The dog had also recently received the "kennel cough" vaccine a few months prior.He reported close contact with the dog, including sharing the bed with his pet.

Discussion
Bordetella bronchiseptica was first isolated and identified in 1911 in dogs, and it was named Bacillus bronchianis [1].Bacillus bronchicanis was chosen since the organism was isolated from the respiratory tracts of dogs suffering from distemper [2].It is a Gram-negative, obligate aerobic coccobacillus known to cause disease in domesticated animals [3].This bacteria is recognized as one of the most common pathogens for canine infectious respiratory disease complex (CIRDC) [4] of Bordetella bronchiseptica are rare, most common in patients with immunodeficiencies and abnormal lung parenchyma; other presentations such as meningitis [3], and bloodstream infections [5] have been described (Table 1).
In a case series of 30 patients of PLWHA, animal exposure history was given for 73% of cases, with 55% reporting animal contact [6].Between 2016 and 2022, the percentage of U.S. households who own dogs increased by 6.1% points, from 38.4% to 44.5%, while the percentage of households that own cats increased by four percentage points, from 25% to 29% [7].Evidence of exposure to Bordetella bronchiseptica is frequently found in healthy and diseased dogs, and client-owned dogs are as likely to be infected as kenneled dogs [4].In an extensive survey of pathogens associated with respiratory disease in multi-cat (5 cats) households in nine European countries, Bordetella bronchiseptica was detected by PCR in 5% of cats from households with the disease and 1.3% without the disease [8].As more Americans are exposed to animals as pets, recognizing and becoming familiarized with this disease is of utmost importance, especially in populations with a higher risk of significant disease as advanced age, immunocompromised, and chronic parenchymal lung disease such as cystic fibrosis.Another concern in the immunocompromised host is the postulation of possible transmission by animals that recently received a live-attenuated, intranasal Bordetella bronchiseptica vaccination [9].
Antimicrobial susceptibility of Bordetella bronchiseptica suggests high resistance rates to beta-lactams, cephalosporins, macrolides, and trimethoprim/sulfamethoxazole but low MICs to tetracyclines and quinolones [10,11].The evidence on treatment is based on animal studies, case reports, and in vitro susceptibility data; treatment duration ranges from 7 to 14 days with monotherapy with doxycycline or levofloxacin; others suggest combination therapy [12].
In conclusion, Bordetella bronchiseptica is an increasingly recognized pathogen with heterogeneous clinical presentations, most commonly presenting with persistent cough and respiratory symptoms but also with isolated bacteremia, meningitis, intrabdominal abscess, and peritonitis.Most cases suggest contact with domesticated animals, suggesting this entity is a zoonosis of clinical importance.A high index of suspicion and a good anamnesis for risk factors is vital in patients with a compatible clinical presentation, especially in patients with immunocompromising conditions.

Table 1
Clinical presentation of Bordetella bronchiseptica in humans.

Clinical presentation
Ref.
1 A 61-year-old man with renal transplant and bacteremia.

Woods et al. [13]
1 A 61-year-old male with HIV/AIDS with fevers, shortness of breath, and intermittent chest pain.

Monti et al. [15]
1 A 77-year-old male with ulcerative colitis on infliximab with traumatic cerebrospinal fluid leak complicated by meningitis.
Radcliffe et al.
Dlamini et al.

Matic et al. [18]
1 A 7-year-old child with cystic fibrosis with persistent and recurrent pneumonia.

Khatib et al. [19]
1 A 7-year-old child status post bone marrow transplant and pneumonia.

Clements et al. [20] 1
A 61-year-old female status post kidney-pancreas transplant with pneumonia after exposure to recently vaccinated dogs.

Gisel et al. [9]
a A total of 11 (50%) patients were female, and the median age was 60 years (range, <1-90).Nineteen patients were admitted to the hospital, and 4 patients (18%) required admission to the intensive care unit.Four patients had repetitive episodes and were the only ones who had documented exposure to dogs or cats.